ABSTRACT The objective of the Human Clinical Phenotyping Core (Core B, HCP) is to promote excellence in human phenotyping, with a central mission to facilitate research on intellectual and developmental disabilities (IDDs) by a diverse interdisciplinary team of investigators across the Einstein/Montefiore campuses. To this end the HCP provides recruitment and sophisticated human phenotyping services for IDDRC investigators (Aim 1). The HCP implements an extensive program of community outreach and recruitment to increase diversity in research on intellectual and developmental disabilities and expose local children to the wonders of science and research (Aim 2). The HCP maintains an extensive and actively growing database of potential research participants (Aim 3) that, in addition to including participant characteristics and clinical and cognitive assessment results, records the presence of neuroimaging data and genetics samples for that participant (Aim 4). This database serves to reduce recruitment and phenotyping costs for investigators, ease the burden of participation for families, and minimize redundant testing efforts across different research groups. De-identified participant information is readily available to IDDRC investigators through this centralized database. The HCP also provides IDDRC members access to state-of-the-art human neuroimaging resources (Aim 5) and engages in the development of next-generation phenotyping tools (Aim 6). Since its inauguration 5-years ago, the HCP has become an integral part of human IDD work at Einstein/Montefiore. For example, it is essential to Einstein's role in an `Autism Centers of Excellence Network' project on the genetics of autism in African Americans (ACE, P50, MH100027), plays a key role in a recently initiated randomized clinical trial testing efficacy of two behavioral interventions on ASD (R01 HD082814), and has been vital to a number of clinical- research partnerships (including on RETT syndrome and NPC type C disease). Over the next 5-years the HCP will continue to support these interwoven aims to promote the mission of the RFK IDDRC to advance diagnosis, prevention, and treatment of children with IDDs. In addition, it will serve the proposed IDDRC research project by recruiting and phenotyping 22q11.2 deletion syndrome participants (Aim 7). Through these aims the HCP will maintain its role as the central hub for a variety of Center investigators for whom comprehensive human phenotyping is key to understanding the implications of their work.